002
FZUS63 KMQT 100202
GLFLS

Open Lake Forecast for Lake Superior
National Weather Service Marquette MI
1001 PM EDT Sat Aug 9 2025

For waters beyond 5 nautical miles of shore on Lake Superior.

Waves are the significant wave height - the average of the
highest 1/3 of the wave spectrum. Occasional wave height is the
average of the highest 1/10 of the wave spectrum.

.SYNOPSIS...

High pressure at 30.2 inches remains centered along the Eastern
Seaboard through the remainder of the weekend. Meanwhile, a 29.6
inch low over the Canadian Prairies this evening lifts to Hudson
Bay, leaving Lake Superior sandwiched between the two features. The
high erodes away on Monday as the low continues over Quebec, sending
a 29.9 inch trough over the lake Sunday evening through Monday. A
secondary trough around 29.7 inches then rotates across the lake
Tuesday and Tuesday evening. High pressure ridging at 30.0 to 30.1
inches then quickly passes over the Great Lakes late in the day
Wednesday into Thursday.


LSZ162-100800-
Lake Superior west of a line from Saxon Harbor WI to Grand
Portage MN beyond 5NM-
1001 PM EDT Sat Aug 9 2025 /901 PM CDT Sat Aug 9 2025/

.REST OF TONIGHT...Southwest winds 5 to 15 knots increasing to
10 to 20 knots after midnight, then diminishing to 5 to 15 knots
late. Waves calm to 2 feet building to 1 to 3 feet, then
subsiding to calm to 2 feet.
.SUNDAY...Southwest winds 10 to 20 knots. Waves calm to 2 feet.
.SUNDAY NIGHT...West winds 10 to 20 knots diminishing to 5 to
15 knots late. Waves calm to 2 feet.
.MONDAY...Southwest winds 5 to 15 knots increasing to 10 to
20 knots by mid afternoon. Waves calm to 2 feet.
.MONDAY NIGHT...Southwest winds 10 to 20 knots increasing to
15 to 25 knots after midnight. A slight chance of showers. A
slight chance of thunderstorms after midnight. Waves building to
1 to 3 feet.
.TUESDAY...West winds 10 to 20 knots. Waves subsiding to calm to
2 feet.
.TUESDAY NIGHT...West winds 10 to 20 knots becoming northwest
5 to 15 knots after midnight. Waves calm to 2 feet.
.WEDNESDAY...Southeast winds 5 to 15 knots becoming east 10 to
20 knots. Waves calm to 2 feet.
.THURSDAY...East winds 10 to 20 knots veering south. A chance of
showers. Waves calm to 2 feet.

$$

LSZ263-100800-
Lake Superior from Saxon Harbor WI to Upper Entrance to Portage
Canal MI 5NM off shore to the US/Canadian border including Isle
Royale National Park-
1001 PM EDT Sat Aug 9 2025

.REST OF TONIGHT...Southwest winds 5 to 15 knots increasing to
10 to 20 knots after midnight, then diminishing to 5 to 15 knots
late. Waves calm to 2 feet building to 1 to 3 feet.
.SUNDAY...Southwest winds 5 to 15 knots increasing to 10 to
20 knots in the afternoon. Waves subsiding to calm to 2 feet.
.SUNDAY NIGHT...Southwest winds 10 to 20 knots becoming west 5 to
15 knots after midnight. Waves calm to 2 feet.
.MONDAY...West winds 5 to 15 knots becoming southwest 10 to
20 knots by mid afternoon. Waves building to 1 to 3 feet.
.MONDAY NIGHT...Southwest winds 5 to 15 knots increasing to 10 to
20 knots after midnight. A slight chance of showers and
thunderstorms after midnight. Waves subsiding to calm to 2 feet,
then building to 1 to 3 feet.
.TUESDAY...Southwest winds 10 to 20 knots veering west by mid
afternoon. Waves building to 2 to 4 feet, then subsiding to 1 to
3 feet.
.TUESDAY NIGHT...West winds 10 to 20 knots becoming northwest
5 to 15 knots after midnight. Waves subsiding to calm to 2 feet.
.WEDNESDAY...North winds 5 to 15 knots veering east. Waves calm
to 2 feet.
.THURSDAY...Southeast winds 5 to 15 knots veering south. Waves
calm to 2 feet.

$$

LSZ264-100800-
Lake Superior from Upper Entrance to Portage Canal to Manitou
Island MI 5NM off shore to the US/Canadian Border-
1001 PM EDT Sat Aug 9 2025

.REST OF TONIGHT...South winds 5 to 15 knots veering southwest
after midnight. Waves calm to 2 feet.
.SUNDAY...South winds 5 to 15 knots veering southwest in the
afternoon, then backing south late. Waves building to 1 to
3 feet, then subsiding to calm to 2 feet.
.SUNDAY NIGHT...South winds 5 to 15 knots veering west late.
Waves calm to 2 feet.
.MONDAY...West winds 5 to 15 knots backing southwest by mid
afternoon. Waves calm to 2 feet.
.MONDAY NIGHT...South winds 5 to 15 knots becoming southwest
10 to 20 knots after midnight. Waves building to 1 to 3 feet.
.TUESDAY...Southwest winds 10 to 20 knots veering west by mid
afternoon. Waves building to 2 to 4 feet, then subsiding to 1 to
3 feet.
.TUESDAY NIGHT...West winds 10 to 20 knots becoming northwest
5 to 15 knots after midnight. Waves subsiding to calm to 2 feet.
.WEDNESDAY...North winds 5 to 15 knots veering east. Waves calm
to 2 feet.
.THURSDAY...Southeast winds 5 to 15 knots veering south. Waves
calm to 2 feet.

$$

LSZ265-100800-
Lake Superior West of Line from Manitou Island to Marquette MI
Beyond 5NM from shore-
1001 PM EDT Sat Aug 9 2025

.REST OF TONIGHT...South winds 10 to 20 knots veering southwest
after midnight. Waves calm to 2 feet.
.SUNDAY...South winds 10 to 20 knots backing southeast late. A
slight chance of showers by mid afternoon. Waves calm to 2 feet.
.SUNDAY NIGHT...South winds 5 to 15 knots veering southwest after
midnight. A slight chance of showers after midnight. Waves calm
to 2 feet.
.MONDAY...West winds 5 to 15 knots. Waves calm to 2 feet.
.MONDAY NIGHT...South winds 5 to 15 knots becoming southwest
10 to 20 knots after midnight. Waves calm to 2 feet.
.TUESDAY...Southwest winds 10 to 20 knots veering west by mid
afternoon. Waves calm to 2 feet.
.TUESDAY NIGHT...West winds 10 to 20 knots veering northwest
after midnight. Waves calm to 2 feet.
.WEDNESDAY...Northwest winds 10 to 20 knots becoming southeast
5 to 15 knots. Waves calm to 2 feet.
.THURSDAY...Southeast winds 10 to 20 knots veering south. Waves
calm to 2 feet.

$$

LSZ266-100800-
Lake Superior East of a line from Manitou Island to Marquette MI
and West of a line from Grand Marais MI to the US/Canadian Border
Beyond 5NM from shore-
1001 PM EDT Sat Aug 9 2025

.REST OF TONIGHT...South winds 10 to 20 knots veering southwest
after midnight, then backing south late. A chance of showers by
midnight. Patchy fog after midnight. Waves calm to 2 feet.
.SUNDAY...South winds 10 to 20 knots. Patchy dense fog through
early afternoon. A slight chance of showers. A slight chance of
thunderstorms by mid afternoon. Waves calm to 2 feet.
.SUNDAY NIGHT...South winds 10 to 20 knots becoming southwest
5 to 15 knots after midnight. A slight chance of showers. Waves
calm to 2 feet.
.MONDAY...Southwest winds 5 to 15 knots veering west by mid
afternoon. A slight chance of showers. Waves calm to 2 feet.
.MONDAY NIGHT...South winds 5 to 15 knots. A slight chance of
showers through midnight. Waves calm to 2 feet.
.TUESDAY...Southwest winds 10 to 20 knots veering west by mid
afternoon. A chance of showers. Waves building to 1 to 3 feet.
.TUESDAY NIGHT...West winds 10 to 20 knots veering northwest
after midnight. Waves subsiding to calm to 2 feet.
.WEDNESDAY...Northwest winds 10 to 20 knots becoming east 5 to
15 knots. Waves calm to 2 feet.
.THURSDAY...Southeast winds 5 to 15 knots becoming south 10 to
20 knots. Waves calm to 2 feet.

$$

LSZ267-100800-
Lake Superior from Grand Marais MI to Whitefish Point MI 5NM off
shore to the US/Canadian border-
1001 PM EDT Sat Aug 9 2025

.REST OF TONIGHT...South winds 10 to 20 knots. A chance of
showers and a slight chance of thunderstorms. Patchy fog after
midnight. Waves calm to 2 feet.
.SUNDAY...South winds 10 to 20 knots. Patchy fog through early
afternoon. A chance of showers and a slight chance of
thunderstorms. Waves calm to 2 feet.
.SUNDAY NIGHT...South winds 10 to 20 knots. A chance of showers
and a slight chance of thunderstorms. Waves calm to 2 feet.
.MONDAY...Southwest winds 5 to 15 knots veering west by mid
afternoon. A chance of showers. Waves calm to 2 feet.
.MONDAY NIGHT...South winds 5 to 15 knots increasing to 10 to
20 knots after midnight. A slight chance of showers. Waves calm
to 2 feet.
.TUESDAY...South winds 10 to 20 knots veering southwest by mid
afternoon. A chance of showers. A chance of thunderstorms by mid
afternoon. Waves calm to 2 feet.
.TUESDAY NIGHT...West winds 10 to 20 knots veering northwest
after midnight. Waves calm to 2 feet.
.WEDNESDAY...Northwest winds 10 to 20 knots veering north. Waves
calm to 2 feet.
.THURSDAY...Southeast winds 10 to 20 knots. Waves calm to 2 feet.

$$

LSZ261-100800-
MAFOR 1003/
Superior West 14520 11520 13510. Waves 1 to 3 feet.

Superior North Central 11410 12510 11410 12420 12410. Waves 1 to
3 feet.

Superior South Central 11410 11510 13410 11310 12410. Waves 2
feet or less.

Superior East 11410 11510 15410. A chance of showers late this
evening and Sunday evening. Waves 1 to 2 feet.

$$

WFO MQT

Experimental modernized open lake forecast is available online at
weather.gov/mqt/glftable

Graphical marine forecasts are available online at:
weather.gov/greatlakes